Every item in the just a dollar store is priced at $1.00. when mary jo opens the store, there is $125.50 in the cash register. when she counts the money in the cash register at the end of the day, the total is $1,085.60. if the sales tax rate is 8.5%, howmany items were sold that day?

885

Step-by-step explanation:

Given:  Amount available in the cash register= $ 125.50.

            Every item is just priced at $1.00

            Total amount of money at the end of day= $1085.60

            Sales tax rate= 8.5%

First finding total revenue generated at the end of day,

Total revenue at the end of day=

∴ Total revenue at the end of day=

Lets assume total number of item sold be "x".

Now, forming an equation to determine the total revenue generated at the end of day.

We know, Total revenue is the number of item sold at $1 and sales tax revenue generated on the number of item sold.

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⇒

⇒

dividing both side by 1.085

⇒

∴ x=

Hence, total number item sold in the day is 885

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation:

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i